Crop engaging apparatus and methods

ABSTRACT

A crop cutting and conditioning apparatus has two vertical axis rotary drum cutters 13, each having an upper rotor with a crop conveying surface 19 and a lower rotor carrying knives 21. Gears drive the upper and lower rotors at different peripheral velocities. The lower rotor has an annular rim 18 having an upper surface shaped to continue the outline of the conveying surface 19. The knives 21 protrude outwardly from beneath the rim 18 and rotate with the rim. The upper rotor has conditioning elements comprising brushes 35 (or sheets of plastics material), for conveying crop and conditioning crop by relative movement between the brushes and the crop. The outer tips of the brushes 35 (or the edges of the sheet or rib-like elements) lie along one or more helical or part helical paths around the rotor axis. Preferably the lower end of each helix leads during the rotation so as to exert a lifting action on crop engaged by the rotors.

The present invention relates to crop engaging apparatus for conveyingand/or treating crops especially, but not exclusively, grasses, and isconcerned in some respects with apparatus for cutting, conditioning andconveying crop. The invention also relates to corresponding methods.

Modern crop cutting devices are usually mowers of the rotary type whichsever the crop by impact, using free swinging knives attached near theperiphery of discs which may be used alone (disc mowers), or which mayform lower skirts of vertical drums which assist in conveying the cutcrop towards the rear of the machine (drum mowers). In each case thediscs which support the knives serve to convey the cut crop to the rear.Knife tip speeds have to be in the broad range of 70 to 90 meters persecond, to ensure clean cutting in most crops and conditions, whereimpact is used. At these speeds it has been found that the powerrequirement for conveying the crop by the discs is very considerable. Insome aspects the invention is concerned with reducing the powerrequirement for cutting the crop and/or for conveying the cut crop.

In some aspects the present invention is concerned with improvedarrangements of combinations of crop conditioning devices with cropcutting devices. Such a device is shown in a previously published U.S.Pat. No. 3,977,165 (Klinner et al) which shows a form of drum cutter inwhich the main upper rotor is driven at a different rate of rotationfrom a lower rotor which carries the cutting knives of the cuttingdevice. In this arrangement, conditioning devices are provided on theupper surface of the crop conveying skirt of the upper drum rotor whichis rotated at a different rate of rotation from the cutting knives. Inpractice a problem arises with such arrangement in that it is difficultto maintain the correct close vertical clearance of the two rotarycomponents, especially when the disc diameter is large and foreignobjects are present on the surface of the field. In some aspects thepresent invention seeks to provide a rotary cutting apparatus of animproved and simplified nature having regard to the drum cuttersdescribed in this U.S. patent specification.

In other aspects, the present invention is directed towards means forconditioning crops. Forage crops such as grasses which are surplus toimmediate requirements are usually cut and field-dried to provide animalfodder, particularly hay or silage, for the feeding of animals whenfresh forage crops are not available. In temperate, especially maritimeclimates, the crops are at risk between cutting and harvesting (i.e. thefield exposure time) because the adverse effects of light and rain andmicro-organism activity can produce appreciable nutrient and dry matterlosses. Accordingly, it is important to minimize the field exposure timeto reduce the risk of such losses. However, the crops cannot beharvested until they have dried to a sufficiently high dry mattercontent for safe storage as animal fodder. In the case of hay, a drymatter content of about 80% is usually required.

The speed at which surface and sap moisture evaporate from the cut cropduring field exposure depends inter alia on the physical condition ofthe crop. The principal barrier to moisture loss is the cuticle and thelayer of epicuticular wax on the crop surface, and it is now commonpractice in agriculture to mechanically treat the crop in order todamage this barrier. Such mechanical treatment, which may take the formof crushing, lacerating, bruising, splitting, bending or scuffing thestem and leaves of the crop, is known as "conditioning". A variety ofconditioning devices have been used or proposed, for example as in UKPat. Nos. 588439 (Chilton), 662303 (Goodall), 1303970 (Bucher Guyer),U.S. Pat. No. 3,977,165 (Klinner et al) and PCT published applicationNo. PCT/GB79/00053--publication No. WO 79/00863 (BSRAE). The earlier ofthe devices described in these publications would often causeundesirable deep tissue damage to the crop resulting in high dry matterand nutrient losses, and were also unsatisfactory when attempts weremade to condition a wide swath of crop, as the complexity and weight ofmachines increased considerably with width. The form of conditioningdescribed in the last of the specifications set out above has allowedconsiderable progress to be made in producing acceptable conditioningwith a light and relatively inexpensive conditioning device, and thepresent invention is concerned in some aspects, although notexclusively, with improvements in relation to the form of conditioningdescribed and claimed in the said PCT patent application.

Another factor which affects the amount of time the crop lies in thefield after cutting is the number of passes required to cut andcondition the crop. In some cases the crop requires three or morepasses, including cutting, conditioning the crop after it has fallen tothe ground, and finally tedding to restructure the swath so that itmaintains a fast drying rate. Many proposals have been made in the pastfor reducing the number of passes by combining cutting and conditioningin a single machine, such combined machines are described, inter alia,in the PCT application numbered above. In another aspect, the presentinvention is particularly concerned, although not exclusively, withapparatus for carrying out in a single pass the cutting and conditioningoperation. In this connection the present invention is concerned in itsmain aspects with cutting and/or conditioning crop by rotary movementabout a vertical axis. Such cutting and conditioning by rotary movementabout a vertical axis is known in itself, for example in the UK Pat. No.1303970 (Bucher Guyer), U.S. Pat. No. 3,977,165 (Klinner et al) and PCTapplication No. PCT/GB79/00053 (BSRAE) mentioned above. In the UKSpecification No. 1303970 (Bucher Guyer) the conditioning rotor isdescribed, inter alia, as a vertical "squirrel-cage" type of rotorrotating behind a vertical axis drum mower, whereas in the U.S. Pat. No.3,977,165 (Klinner) the conditioning devices are described asconditioning elements mounted on the upper surface of the crop conveyingskirt of a vertical axis drum mower. The PCT application No.PCT/GB79/00053 (BSRAE) mentions the possibility of two counter-rotatedbrushes fitted vertically so as to cover the opening between the drum oftwo-drum mowers to give a simple swath-forming arrangement. The brushesare described as being cylindrical or conical.

There have also been known previously a number of forms of cropconveying rotors having outwardly directed crop conveying elements. Oneform of such crop conveying elements has been provided by rotorsgenerally in the form of paddle wheels with flat sheet like conveyingelements extending longitudinally along the length of the conveyingrotor. Such paddles were sometimes straight edge, and sometimes shapedwith serrations or other patterns. Examples of previous disclosures ofsuch rotors are to be found in U.S. Pat. No. 3,676,988 (Bucher-Guyer)which shows in FIG. 9 a horizontal conditioning rotor provided withbeater bars 4b formed with saw-teeth shaping. Another prior patent, UKPat. No. 1140284 (Landbruksteknisk) shows in FIG. 2 at 15 a feed rollerthe free edges of which are said to be preferably waved or saw-toothed.Also in UK Pat. No. 1214840 (Vissers) there is disclosed a paddle wheeltype of conveying rotor which it is said may be made of sheet metal orof synthetic plastics material, rubber or like flexible elasticmaterial.

As has been mentioned, our own previously published UK pending PatentApplication No. 8012426 shows pick-up and conveying rotors includingoutwardly directed crop engaging elements, which may be formed ofsynthetic plastics material.

In our prior granted UK Pat. No. 1322165, before amendment, there isdisclosed in FIGS. 1 to 3 a crop conditioning device in which a rotorhas a number of outwardly directed conditioning elements formed oflengths of rubber regularly disposed about the axis of the rotor.

According to the present invention there is provided crop engagingapparatus comprising a mobile frame for movement over the ground, one ormore crop engaging rotors for conveying and/or treating cut crop, anddrive means for rotating the or each rotor about a vertical axis, ornear vertical axis, for conveying cut crop towards the rear of themachine, in which the or each rotor has one or more crop engagingelements arranged with an edge or edges thereof, or with an array ofdistal ends thereof, lying along one or more helical or part helicalpaths around the rotor axis, the helical or part helical paths beingarranged with the lower end of the or each helix leading so as to exerta lifting action on crop engaged by the rotor.

In one preferred form, the or each rotor has a plurality of cropengaging elements distributed around the axis of the rotor, each elementcomprising a generally flat sheet or rib-like member having an outwardlyfacing edge for engaging crop.

Conveniently the crop engaging elements are formed by a plurality ofwide, generally flat rib-like members spaced from and distributed aroundthe axis of the rotor, each rib-like member having a generallongitudinal axis which is inclined at a skew angle to the axis of therotor, and in one form each rib-like member has a generallycrescent-shaped form, the outer edge of the rib being of curved shape.

It is to be appreciated that the helix need not be formed by curvedouter edges of the elements, in that the outer edges may be straight,but may merely be arranged to provide the overall effect of a helix.However it is convenient in some arrangements for the outer edges to becurved.

The invention in this aspect finds particular application where the cropengaging elements are formed of thick stiff resilient and generally flatmaterial (for example thick stiff resilient sheet-like material),conveniently of synthetic plastics material. Suitable materials for thecrop engaging elements are, for example, polyethylene, nylon, andpolypropylene.

The shape of each such crop engaging element may vary between a rib-likemember with a longitudinal edge engaging the crop, and an outwardlydirected fin having a length in the said outwardly extending directiongreater than its width.

In accordance with another preferred form of the invention, the rotorcomprises a brush-like structure having a multiplicity of stiff,resilient, outwardly directed, elongate elements for picking up andconveying the crop by an action including relative movement between theconveying elements and the crop engaged thereby, the elements beingyieldable in response to engagement with the crop, and being yieldableat least predominantly by bending of the elements along at least part ofthe crop engaging portions of the lengths thereof, and the elementsbeing sufficiently stiff to return to their undeflected dispositionswhen free from engagement with crop at least predominantly by virtue ofthe stiffness of the elements. Most preferably, in this form, theelements are arranged in spaced-apart tufts of elements.

Where reference is made to the elements being sufficiently stiff toreturn to their undeflected dispositions at least predominantly byvirtue of the stiffness of the elements, it is to be appreciated thatthe base of an element may be secured to a support member by a mountingwhich has itself a degree of resilience, for example by being clamped toa support member by clamping means including resilient material. Such aresilient mounting may contribute to the return of an element to itsundeflected disposition, but it is a feature that the elements aresufficiently stiff to return to their undeflected dispositionspredominantly by virtue of the stiffness of the elements. Where, theelements are mounted in tufts with a plurality of elements set closelytogether, it will be appreciated that adjacent elements will assist eachother in the return to an undeflected disposition when free fromengagement with crop, but again it will be appreciated that this returnis effected predominantly by virtue of the stiffness of the elements.Similarly the return of the elements to their undeflected dispositionsmay be assisted by the effects of centrifugal force, but again theelements are returned predominantly by virtue of the stiffness of theelements.

Conveniently the elements may be arranged in a brush of conventionalform, that is to say in which groups of elements are mounted together intufts, and the positions of the tips of the elements are to at leastsome extent random. However other forms of brush will be readilyapparent, and in particular the brush may comprise elements which aredisposed in a regular, non-random, pattern.

It is preferred that the elements are sufficiently stiff to penetrate astream of crop being conveyed and to convey the crop with a degree ofslippage between the elements and the crop. It is further preferred thatthe elements are yieldable by bending substantially along the whole ofthe free lengths thereof.

In one form, the elements may be arranged in spaced apart tufts ofelements and the population of the elements in each tuft at the tips maylie in the range 1 to 20 elements per sq. cm, preferably in the range 3to 16 elements per sq. cm.

Conveniently each tuft may be formed of one or more lengths of elementmaterial doubled over and secured within a protective, resilientretaining sleeve or tube to a supporting base in the region of the foldof the doubled over element length or lengths.

Conveniently each element or group of elements in a tuft may besupported and protected at the base thereof by a sleeve of resilientmaterial.

In general terms, the conditioning elements may be of the form describedin the published P.C.T. patent application No. PCT/GB79/00053.

In accordance with another feature of the present invention there isprovided in association with the or each crop engaging rotor, a rotarycutting means mounted for rotation about the same axis as the cropengaging rotor, and arranged to be driven by the drive means for cuttingcrop by rotary motion during movement of the frame over the ground, theassociated crop engaging rotor being arranged to lift and conveyrearwardly crop cut by the cutting means. In a preferred form the drivemeans is arranged to drive the or each rotary cutting means at adifferent angular velocity from its associated crop engaging rotor. Insome cases where a rotary cutting means is provided it is advantageousto arrange that the crop engaging elements of the rotor extend outwardlybeyond the outer perimeter of the cutting path of the cutting means.

By the term different angular velocities is meant that the first andsecond rotors of each cutting device are rotated with different angularrates of rotation and/or in different directions of rotation.

In preferred arrangements of the present invention, it is possible toprovide rotary mowers on which the cutting knives are driven at theoptimum speed for impact cutting, i.e. between approximately 70 and 95m/s, but the crop conveying rotors are driven at a very much lowerspeed, so that conveying and conditioning devices attached to them willneither fragment the crop excessively nor propel foreign objectsdangerously.

Although embodiments of the invention may be constructed in which only asingle crop engaging rotor is provided, there will normally be providedtwo or more crop engaging rotors positioned side by side relative to thedirection of forward travel of the apparatus. In particularly preferredforms, there is provided a pair of crop engaging rotors, each rotorbeing mounted for rotation about a vertical or near vertical axis withthe vertical axes spaced apart transversely relative to an intendeddirection of forward travel of the apparatus, and the drive means beingarranged to drive the rotors in counter rotation in such a manner thatcrop is passed between the rotors upwardly and rearwardly from the frontto the rear of the apparatus. In such a case the rotors have oppositelywound helixes, and are rotated in opposite directions, so that cut cropis drawn upwardly and rearwardly through the gap between the rotors.

Where there are provided cutting means in association with the cropengaging rotor or rotors, the said axis or axes about which the rotor orrotors are rotated will normally be vertical, that is to say verticalwhen the apparatus is standing on horizontal ground. Where the cropengaging rotor or rotors are used without associated cutting means, theaxis or axes of rotation may be inclined to the vertical, for example atan angle of up to 25° from the vertical.

In accordance with another preferred feature, where a pair of rotors arepositioned side by side, there may be provided apparatus in which theouter peripheries of the two crop engaging rotors overlap, in which thedrive means is arranged to rotate the two crop engaging rotors incounter rotation at the same rate of rotation, and in which the cropengaging elements are so arranged that in operation elements of onerotor intermesh with spaces between elements on the other rotor duringrotation.

In accordance with another arrangement, apparatus may be provided wherea pair of rotors are positioned side by side, and are driven to rotatein the same directions of rotation, that is to say not intermeshing.

With no cutting means present this leads to crop being swept across thecombined front of the rotors into a windrow on one or other side of themachine, depending on the direction of rotation.

There is also provided in accordance with the invention a method ofconveying crop comprising the steps of rotating about a vertical or nearvertical axis a crop engaging rotor mounted on a mobile frame formovement over the ground, and conveying crop towards the rear of theframe by rotation of the rotor, the conveying step including conveyingthe crop rearwardly by movement of the periphery of the rotor, andlifting the crop by an augering action of the rotor.

The invention finds particular usefulness where the method includes thesteps of cutting crop by rotation of a rotary cutting means mountedcoaxially with the crop engaging rotor, and conveying and lifting thecut crop by the conveying and augering action of the crop engagingrotor, particularly when including the step of rotating the rotarycutting means and the crop engaging rotor at different angularvelocities.

The invention finds particular advantage where the method includes thesteps of rotating two crop engaging rotors about respective vertical ornear vertical axes which are spaced apart transversely relative toforward motion of the rotors, rotating the two rotors in counterrotation in such a manner that crop is passed between the rotorsupwardly and rearwardly from the front to the rear of the apparatus by aconveying and augering action of both rotors. However it is to beunderstood that a greater number of rotors may be spaced transversely inline or in open or closed V-formation for treating, scattering orgathering into a windrow, crop from a wide strip of field surface area.

Embodiments of the invention will now be described by way of examplewith reference to the accompanying drawings in which:

FIG. 1 is a cross-section showing from the front the outer half of atwin unit, two-speed crop cutting apparatus for use in an embodiment ofthe invention, and generally of the drum mower kind;

FIG. 2 is a front view partly in cross-section of a modified form of thecrop cutting apparatus of FIG. 1;

FIG. 3 is a diagrammatic perspective view of the general layout of acrop cutting apparatus for use in an embodiment of the present inventionas shown in the preceding Figures;

FIGS. 4 and 5 are side and plan diagrammatic representationsrespectively of a modification of a crop cutting apparatus of the formshown in the preceding Figures;

FIGS. 6, and 6(a); 7 and 7(a); and 7(b) and 7(c); are diagrammatic sideand plan views respectively of a further modification of the cropcutting apparatus shown in the preceding Figures, in which a lower rotorincludes discrete projecting portions;

FIGS. 8 and 8(a) show a side cross-section and plan view respectively ofa crop cutting apparatus suitable for use in connection with the cropcutting apparatus shown in the preceding Figures;

FIG. 9 is a diagrammatic side view of crop cutting and conditioningapparatus embodying the invention in which an array of conditioningelements is provided on an upper rotor of a crop cutting device;

FIGS. 10 and 10(a) show diagrammatic perspective views of a crop cuttingand conditioning device embodying the invention utilising brush-likeconditioning elements;

FIG. 11 shows a diagrammatic perspective view of a modification of thecrop cutting and conditioning device shown in FIG. 10; and

FIGS. 12 and 12(a) are perspective views of an alternative form of cropcutting and conditioning apparatus embodying the invention and utilisingrib-like conditioning elements.

FIG. 1 is a cross-section showing from the front the outer half of atwin unit, two-speed crop cutting apparatus embodying the invention andgenerally of the drum mower kind. From a transverse drive shaft 11 acetre spindle 12 of the drum cutter indicated generally at 13 is drivenby means of two bevel gears 14. At its base the spindle 12 runs in athrust bearing 15 and has attached to it a skid disc 16 which is freelyrotatable in known manner. Above the skid disc 16 there is fixedlyattached to the spindle 12 a support disc 17 which constitutes a first,lower rotor of the cutting device and which carries a narrowfrusto-conical rim 18 which may for example be 50 mm wide. The shape ofthe rim 18 is such that its sloping upper surface is a continuation ofthe shape of a crop conveying skirt 19 attached to the base of thecentral drum 20 of the cutting device 13. Pivoted knives 21 are attachedto the underside of the narrow rim 18 in such a way that upon meeting anobstruction each knife can swing through 360°. The knife carrying rim 18is entirely smooth on its crop facing surface and may for example becoated with polytetrafluoroethylene or other durable low frictionmaterial. At the position of each knife 21, recesses in the disc 17allow the knife to pivot underneath the rim 18, through 360°, uponstriking and obstruction on the ground.

The drum 20, skirt 19 and internal supporting webs 22 constitute asecond, upper rotor which is mounted by bearings 23 and 24 on thecentral spindle 12, and is driven from the transverse shaft 11 at thetop by a second pair of bevel gears 25 and through a gear wheel 26 andinternal gear ring 27. The speed at which the upper rotor 19-20, isdriven may for example be 20 m/s at the circumference of the cropconveying skirt 19, but may in other cases be in the range 10 m/s to 40m/s. As shown in FIG. 1 by the two arrows, both the knife carrying rim18 and the crop conveying skirt 19 rotate in the same direction, namelytowards the rear on the inner side of the cutting device 13 which facestowards the other cutting device (not shown). Thus in conventionalmanner the crop is gathered inwardly between the two cutting devices andtransferred rearwardly to form a swath. Thus on the second cuttingdevice (not shown) the rotating components revolve in the oppositedirection so that the crop is conveyed to the rear through the centralspace between the adjacent devices.

FIG. 2 is a front view partly in cross-section of a modified form of thecrop cutting apparatus of FIG. 1, and in this and other embodimentscorresponding elements are indicated by like reference numerals. In thismodification the bevel gears 14 and 25 are so arranged that the knifecarrying rim 18 rotates in the opposite direction to the direction ofrotation of the crop conveying skirt 19.

With regard to the gearing shown in FIGS. 1 and 2, it will beappreciated that alternative ways of achieving the differential drivemay be provided, such as planetary gearing.

It is not essential that the cutting rotor rotates more quickly than theconveying and conditioning rotor. If a method is used which achieves thedesired crop cutting at lower speeds than the lowest effectiveconditioning speeds of, say, 15 m/s, then the ratio of the speedsbetween cutting and conditioning components may be reversed.

FIG. 3 is a diagrammatic perspective view of the general layout of cropcutting apparatus embodying the invention in the form shown in FIG. 1 orFIG. 2, but with attachments 28 attached to the upper surfaces of thecrop conveying skirts 19. The attachments 28 are support bars intendedfor mounting crop conveying and/or conditioning elements to be describedand shown hereinafter. The two crop cutting devices are indicatedgenerally at 13 and 13' and are shown as supported from an overheadframe 29 suitable for attachment to the three point linkage of atractor.

FIGS. 4 and 5 are side and plan diagrammatic representationsrespectively of a modification of the crop cutting apparatus of the formshown in the preceding figures, and again corresponding elements areindicated by the like reference numerals. FIG. 4 shows the skid disc 16at the base of the cutting device, and a disc 17 which carries the outerrim 18 and knives 21.

FIG. 4 shows how the knife carrying rim 18 is attached to the supportdisc 17 by means of spaced apart angled brackets 33. This method ofconstruction ensures that any material which may enter through the gapbetween the knife carrying rim 18 and the crop conveying skirt 19 canleave again through the gaps between brackets 33 under the influence ofcentrifugal forces. The plan view in FIG. 5 shows how the pivoted knives21 can rotate through 360°, between the brackets 33.

FIGS. 6 and 6(a) are diagrammatic side and plan views respectively of afurther modification of the crop cutting apparatus shown in thepreceding figures, in which the lower support disc 17 consists of adished pressing from which smaller discs have been cut as indicated at17' to save weight. To provide locating and mounting means for theknives 21, part-moon shaped plates 18' are welded to an upstanding rim17" which is also recessed at the top to allow each knife to swingthrough a full 360°, on impact with a heavy object. In thismodification, the projections 18' fulfill a similar function to the rim18 in the preceding figures, and as shown in FIG. 6, the shape of eachprojection 18' is such as to continue the shape of the upper surface ofthe crop conveying skirt 19. In a modified version shown in FIGS. 7 and7(a), each plate is in the form of a ramp acting to lift cut croptowards the conveying surface 19 of the upper rotor.

Although it is preferred that the knives 21 are mounted beneath theprojections 18', or the rim 18, it is to be appreciated that the knivescould be mounted on top of the projections 18' or rim 18. Furthermore,the knives could be fixedly or semi-rigidly mounted without pivotting.

The embodiments of FIGS. 6 and 7 give the advantage that the overlapzone between two adjacent, counter rotating and synchronously drivencutting units can be made greater than is possible with plain discunits. As a result the "mane" of long stubble so often left in difficultcrops and conditions by rotary mowers is avoided.

It should be understood that the shape of the ramp-like protrusions inFIGS. 6, 6(a), 7 and 7(a) can be varied; the most preferred shape is theleading half of a part-moon, as in FIG. 7(a).

In FIG. 7(b) there is shown in plan view an alternative form of therotor 17 for supporting the knives 21, although in FIG. 7(b) the knivesare omitted. FIG. 7(c) is a cross-section along the lines A--A in FIG.7(b), and shows one of the knives 21, and also the relationship of therotor 17 to the conveying rotor surface 19. Thus in general it will beappreciated that the cutting knives can be attached to upturned ordownturned spoke-like extensions of a lower rotor of small centrediameter, in such a way that the upper surface of each knife liesapproximately in the continuation plane of the crop conveying surface ofthe upper rotor.

FIGS. 8 and 8(a) show a side cross-section and plan view respectively ofan apparatus embodying the present invention and suitable for use inconnection with the crop cutting apparatus shown in the precedingfigures. FIG. 8 shows a wiper device 34 in the form of a tuft ofresilient crop conditioning elements (also referred to as filaments) 35formed of synthetic plastics material. The tuft 34 is bolted onto thecrop conveying skirt 19 in such a way that it is supported on two sidesby a shallow bracket 36 to prevent the tuft from turning under theinfluence of centrifugal force or load applied to its tip. In the planview FIG. 8(a), the tuft 34 is shown to be orientated in such a waythat, relative to a radius of the crop conveying skirt 19, the tips ofthe elements 35 are trailing. It is also shown that the elements 35overhang the knife carrying rim 18 and may extend over the cutting pathof the cutting knives 21. The number of wiping tufts 34 fitted near theperimeter of the crop conveying skirt 19 may varied from two per disc toseveral times the number of cutting knives.

The wiper element of FIGS. 8 and 8(a) overhanging the cutting rim is notprimarily for conditioning the crop; it also serves the purpose ofengaging, lifting or assisting crop on to the conveying skirt andprevents repeated contact of crops with the cutting knives. Optionallyit can intrude into the cutting zone. The degree of resilience and itsconstruction can vary.

FIG. 9 is a diagrammatic side view of a crop cutting and conditioningapparatus embodying the invention and is particularly concerned with alinear array 37 of crop conditioning elements 35 which are provided onthe crop conveying skirt 19 of a crop cutting and conditioning device13. FIG. 9 shows a knife carrying rim 18 of the form described withreference to the previous figures, and also shows a tuft 34 protrudingout over the rim 18. The rim wiping tuft 34 is shown to be followed byan attachment to the crop conveying skirt 19 which consists of arear-wardly leaning bracket plate 38 to which are attached on theupwardly inclined trailing face thereof a series of tufts 39 ofsynthetic plastics conditioning elements 35 similar to the elementsdescribed with reference to FIG. 8(a). The conditioning elements of theembodiments described with reference to FIG. 8 onwards of the presentdescription may conveniently be of any of the forms described inpublished pending PCT Application No. PCT/TB79/00053-Publication No.W079/00863. It is an object of the attachment shown in FIG. 9 as a wholeto drive itself under the cut crop, forcing the crop upwards so that itis scratched and abraded by the tufts of plastics material duringacceleration. To maintain the drum unit of the cutting device 13 inbalance in operation, two attachments 38 are normally required, althoughalternatively a counter-weight may be fitted on the opposite side of thecrop conveying skirt 19 and this may be appropriate on a relativelysmall diameter cutting device. Preferably the multi tuft attachment 37is fitted at an angle to a radius of the vertical axis of the cuttingdevice 13 so that the outer end of the attachment 37 leads the radius.The angle which the attachment 38 makes with a radius of the verticalaxis of the cutting device 13 (when viewed from above) determineswhether the crop is scattered at the rear of the mower or whether it isformed into a distinct swath. In FIG. 9 the inclination of the cropconveying skirt 19 has been accentuated by the base of the attachment 38being tapered down towards the rim. This configuration makes it moredifficult for the crop to move towards the centre of the crop conveyingskirt 19, and conditioning is largely confined to the lower cropregions.

FIGS. 10 and 10(a) are diagrammatic perspective views of a furtherembodiment of a crop conditioning device embodying the invention, inthis case where conditioning elements are provided on bars 43 positionedto extend between the outer edge of the conveying skirts 19, and theupper part of the drum 20. The bars are arranged in the general form ofa conical "squirrel cage" arrangement, and represent a further movementof the conditioning elements from the positions shown in FIG. 9, so asto be lying at an even steeper angle to the plane of the conveyingskirt. The conditioning bars are so fitted that they connect the uppersurface of the crop conveying skirt 19 with the underside of an uppersealing ring 44 attached to the top of the drum 20. In FIG. 10, brushtufts 45 are shown set substantially horizontally, whilst in FIG. 11,which shows a modification, the tufts 45 are inclined downwardly in theoutward direction. In FIGS. 10 & 11 the lower parts of the bars lead theupper parts, relative to the rotation of the rotors, forming a helicalarrangement in order to give a lifting effect to the crop.

The crop conditioning unit need not necessarily be of open cageconstruction, but can consist of a solid cone or drum to which fins formounting the conditioning elements can be attached.

A further alternative embodiment of the invention will now be describedwith reference to FIG. 12 which shows a perspective view of the generallayout of a crop cutting and conveying apparatus embodying the presentinvention. Many of the components of the apparatus shown in FIG. 12 arein common with the structures shown in FIGS. 1, and 1(a), and likereference numerals are used for like elements. The description of FIG.12 should be read in conjunction with FIGS. 1, and 1(a).

The apparatus comprises a crop cutting and conveying apparatus havingtwo cutting units indicated generally at 108 and 109, each comprising amain central drum 20 suspended from a cross beam 29, and each having adish shaped outwardly sloping skirt 19 and dish shaped ground skid 16.Cutting knives 21 protrude outwardly from a separate disc 17 between theskirt 19 and the ground skid 16, so that in general terms the two drums108 and 109 resemble conventional drum cutting units.

Mounted on each of the cutter units is a plurality of crop engagingelements 110, embodying this aspect of the present invention. Each cropengaging element 110 comprises a generally crescent-shaped, flat,rib-like member of stiff resilient synthetic plastics material, forexample 9 m.m. thick, which is secured to the drum cutter by beingbolted to support bars 130 which in turn are secured between the skirt19 and an upper support structure 131. Outwardly projecting bars 132form part of the support structure 131 to which a support bar 130 isbolted. Each support bar 130 is inclined at a skew angle to the axis ofrotation of the drum 20, and an outwardly facing edge 133 of the cropengaging element 110 is generally curved in a crescent shape. The effectof this inclination of each crop engaging element 110 is that the outeredges of the elements provide a general configuration of a number ofpart helixes around the drum 20. The drive means for the drum [asdescribed hereinbefore with reference to FIG. 1] is arranged to drivethe rotors in rotation in a sense such that the lower edge of each helixis leading, so as to impart a lifting action to the crop.

Preferably the outer edge of each crop engaging element 10 is serratedas at 134 to assist in the crop engaging action but the outer edges maybe smooth or scalloped.

Attachment of the elements 10 may be to mounting bars or fins by boltscarrying optionally coil spring spacers, to make provision for greaterdeflection than can normally occur when a heavy object is accidentallypicked up with the crop and makes contact, perhaps repeatedly, with oneor more ribs.

The speed at which the main rotor 20 is driven may for example be 20 m/sat the circumference of the crop conveying skirt 19, but may in othercases be in the range 10 m/s to 40 m/s. This speed is arranged to beslower than the speed of rotation of the cutting knives 21, which arerotated at a conventional cutting speed. Both the knife carrying disc 17and the crop conveying skirt 19 on the rotor 108 rotate in the samedirection, namely towards the rear on the inner side of each cuttingdevice, so that in conventional manner the crop is gathered inwardlybetween the two cutting devices and transferred rearwardly to form aswath. Thus on the second cutting device 109, the rotating componentsrevolve in the opposite direction so that cut crop is conveyed to therear through the central space between the adjacent cutting devices.

In operation the arrangements by which the planes of the crop conveyingelements 110 are helically inclined to the vertical rotary axis has theeffect of an auger which enters under any crop which overhangs the frontof the cutting unit and lifts the crop, sometimes even before the cropis cut by the knives 121. The crop engaging elements 110 act like ascrew thread driven under the crop and impart a lifting force to thecrop. Conveniently at the same time the crop engaging elements 110 arearranged to condition the crop so as to deliver a formed swath which isalso conditioned for crop drying.

The crop engaging elements 110 can be attached to their mounting bars130 rigidly, so that deflection arises from the nature of the materialof the elements themselves, or conveniently the elements can be attachedusing coil spring washers in the securing bolts. In such a case the riblike members can readily deflect upwards or downwards more easily and bya greater extent than would be possible for rigidly attached elements.

Advantages which may be obtained from embodiments of the inventioninclude the following. There may be provided a particularly compactmower conditioner. Due to the forward motion of the machine, cut crop isconditioned immediately in a thin layer. Laid crops may be liftedeffectively at the front and protected to some extent against multiplecutting. The crop is augered upwards, lifted over the knives at therear, and deposited in a very fluffy swath. The smooth edges of the cropengaging rib like members at the bottom and top minimise powerrequirements and damage to the susceptible upper crop partsrespectively. The unit shown in the Figures is also suitable for frontmounting purposes on a drive unit such as a tractor, but is shown inFIG. 10(a) side mounted on a tractor.

In accordance with a particularly preferred feature, the outer edges ofthe elements 110 are extended beyond the outer perimeter of the cuttingpaths of the knives 21, and the elements 110 of the two rotors 108 and109 are arranged to overlap and intermesh in the region between therotors, in the manner of two gear wheels. This provides particularlyeffective conditioning of the crop. If additionally the knife carryingdiscs 17 are driven in counter-rotation, cutting of the crop is achievedat least in part by shear.

I claim:
 1. Crop engaging apparatus comprising:a mobile frame for movement over the ground, at least one crop engaging rotor for conditioning and conveying cut crop, and drive means for rotating said rotor about a vertical axis, or near vertical axis, for conditioning cut crop and conveying the crop towards the rear of the machine, the rotor comprising a brush-like structure having a multiplicity of stiff, resilient, outwardly directed, elongate crop engaging elements, crop engaging being arranged in a plurality of part helical arrays distributed around the rotor axis, each said array occupying only part of the circumference of said rotor, and each said array leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, each said array comprising a lower part close to the ground, and an upper part which is spaced from the ground, crop engaging protruding outwardly from said rotor axis both at said lower part of said array and at said upper part of said array, the distal ends of crop engaging forming an outer envelope of said rotor over a substantial proportion of the height of said rotor so that said distal ends of crop engaging exert a conditioning action on the crop.
 2. Apparatus according to claim 1 in which the elements are arranged in spaced-apart tufts of elements.
 3. Crop engaging apparatus comprising:a mobile frame for movement over the ground, at least one crop engaging rotor for conditioning and conveying cut crop, and drive means for rotating said rotor about a vertical axis, or near vertical axis, for conditioning cut crop and conveying the crop towards the rear of the machine, said rotor comprising a plurality of crop engaging elements extending outwardly from said rotor axis and distributed around said rotor axis, each said element occupying only part of the circumference of said rotor, and said plurality of elements being greater than two, each element comprising a generally flat sheet-like member, said member having an outwardly facing edge for engaging crop, each said element terminating in another crop engaging edge leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, said outer edges being inclined upwardly and rearwardly over at least a major proportion of the height of the crop engaging region of the rotor, each said outer crop engaging edge comprising a lower part close to the ground, and an upper part which is spaced from the ground, said outer edge of each element protruding outwardly from said rotor axis both at said lower part of said edge and at said upper part of said edge, said outer edges of said elements forming an outer envelope of said rotor over a substantial proportion of the height of said rotor so that said outer edges exert a conditioning action on the crop.
 4. Apparatus according to claim 3 in which there is provided in association with the crop engaging rotor, a rotary cutting means mounted for rotation about the same axis as the crop engaging rotor, and arranged to be driven by the drive means for cutting crop by rotary motion during movement of the frame over the ground, the associated crop engaging rotor being arranged to lift and convey rearwardly crop cut by the cutting means.
 5. Apparatus according to claim 4 in which said drive means is arranged to drive said rotary cutting means at a different angular velocity from its associated crop engaging rotor.
 6. Apparatus according to claim 4 in which the elements of the rotor extend outwardly beyond of the outer perimeter of the cutting path of the cutting means.
 7. Apparatus according to claim 3 in which there are provided two crop engaging rotors having the features set out in claim 3, each rotor being mounted for rotation about a vertical or near vertical axis with the axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and the drive means being arranged to drive the rotors in counter rotation in such a manner that crop is passed between the rotors upwardly and rearwardly from the front to the rear of the apparatus.
 8. Apparatus according to claim 7 in which the outer peripheries of the two crop engaging rotors overlap, in which the drive means is arranged to rotate the two crop engaging rotors in counter rotation at the same rate of rotation, and in which the crop engaging elements are so arranged that in operation the outer edges of elements of one rotor intermesh with spaces between the outer edges of elements on the other rotor during rotation.
 9. Apparatus according to claim 3 in which there are provided two or more crop engaging rotors having the features set out in claim 3, each rotor being mounted for rotation about a vertical or near vertical axis with the axes spaced apart transversely relative to an intended direction of forward travel of the apparatus, and the drive means being arranged to drive each rotor in rotation in the same sense in such a manner that crop is swept across the combined front of the rotors into a windrow on one or other side of the apparatus.
 10. Apparatus according to claim 3 in which the general outline of the outer edge of each element is straight.
 11. Apparatus according to claim 3 in which the general outline of the outer edge of each elements is curved.
 12. Apparatus according to claim 3 in which each succeeding element around the periphery of the rotor is overlapped by the immediately preceding element, each element having an upper portion which extends over a lower portion of an immediately succeeding element.
 13. Apparatus according to claim 3 in which the envelope of the outer edges of the elements of the rotor is substantially cylindrical.
 14. Apparatus according to claim 3 in which the envelope of the outer edges of the elements of the rotor is at least part conical.
 15. Crop engaging apparatus comprising:a mobile frame for movement over the ground, at least one crop engaging rotor for conditioning and conveying cut crop, and drive means for rotating said rotor about a vertical axis, or near vertical axis, for conditioning cut crop and conveying the crop towards the rear of the machine, said rotor comprising a plurality of crop engaging elements extending outwardly from said rotor axis and distributed around said rotor axis, each said element occupying only part of the circumference of said rotor, and said plurality of elements being greater than two, each element comprising a generally flat sheet-like member, said member having an outwardly facing edge for engaging crop, each said member being formed of thick stiff resilient sheet-like material, each succeeding element around the periphery of the rotor being overlapped by the immediately preceding element, each element having an upper portion which extends over a lower portion of an immediately succeeding element, each said element terminating in an outer crop engaging edge leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, said outer edges being inclined upwardly and rearwardly over at least a major proportion of the height of the crop engaging region of the rotor, each said outer crop engaging edge comprising a lower part close to the ground, and an upper part which is spaced from the ground, said outer edge of each element protruding outwardly from said rotor axis both at said lower part of said edge and at said upper part of said edge, said outer edges of said elements forming an outer envelope of said rotor over a substantial proportion of the height of said rotor so that said outer edges exert a conditioning action on the crop.
 16. Crop engaging apparatus comrising:a mobile frame for movement over the ground, at least one crop engaging rotor for conditioning and conveying cut crop, and drive means for rotating said rotor about a vertical axis, or near vertical axis, for conditioning cut crop and conveying the crop towards the rear of the machine, said rotor comprising a plurality of crop engaging elements extending outwardly from said rotor axis and distributed around said rotor axis, each said element occupying only part of the circumference of said rotor, and said plurality of elements being greater than two, each element comprising a generally flat sheet or rib-like member, said member having an outwardly facing edge for engaging crop, each said element terminating in an outer crop engaging edge leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, said outer edges being inclined upwardly and rearwardly over at least a major proportion of the height of the crop engaging region of the rotor, each said outer crop engaging edge comprising a lower part close to the ground, and an upper part which is spaced from the ground, said outer edge of each element protruding outwardly from said rotor axis both at said lower part of said edge and at said upper part of said edge, said outer edges of said elements forming an outer envelope of said rotor over a substantial proportion of the height of said rotor so that said outer edges exert a conditioning action of the crop.
 17. Apparatus according to claim 16 in which the crop engaging elements are formed by a plurality of wide, generally flat rib-like members spaced from and distributed around the axis of the rotor, each rib-like member having a side edge facing outwardly from the axis for engaging crop, and each rib-like member having a general longitudinal axis which is inclined at a skew angle to the axis of the rotor.
 18. Apparatus according to claim 17 in which each rib-like member has a generally crescent-shaped form, the outer edge of the rib being of curved shape.
 19. Crop engaging apparatus comprising:a mobile frame for movement over the ground, at least one crop engaging rotor for conditioning and conveying cut crop, and drive means for rotating said rotor about a vertical axis, or near vertical axis, for conditioning cut crop and conveying the crop towards the rear of the machine, said rotor comprising a plurality of crop engaging elements extending outwardly from said rotor axis and distributed around said rotor axis, each said element occupying only part of the circumference of said rotor, and said plurality of elements being greater than two, each element comprising a generally flat sheet-like member, said member having an outwardly facing edge for engaging crop, each said element terminating in an outer crop engaging edge leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, said outer edges being inclined upwardly and rearwardly over at least a major proportion of the height of the crop engaging region of the rotor, each said outer crop engaging edge comprising a lower part close to the ground, and an upper part which is spaced from the ground, said outer edge of each element protruding outwardly from said rotor axis both at said lower part of said edge and at said upper part of said edge, said outer edges of said elements forming an outer envelope of said rotor over a substantial proportion of the height of said rotor so that said outer edges exert a conditioning action on the crop, and a rotary cutting means mounted for rotation about the same axis as said crop engaging rotor, said cutting means being driven by said drive means for cutting crop by rotary motion during movement of said frame over the ground, and said associated crop engaging rotor being arranged to lift and convey rearwardly crop cut by the cutting means, said drive means being arranged to drive said cutting means at a different angular velocity from said crop engaging rotor.
 20. A method of conditioning and conveying crop comprising the steps of:rotating about a vertical or near vertical axis a crop engaging rotor mounted on a mobile frame for movement over the ground, and conditioning crop and conveying crop towards the rear of the frame by rotation of said rotor, said conditioning and conveying step comprising acting on the crop by a plurality of crop engaging elements extending outwardly from said rotor axis and distributed around said rotor axis, each said element occupying only part of the circumference of said rotor, and said plurality of elements being greater than two, each element comprising a generally flat sheet-like member, said member having an outwardly facing edge for engaging crop, each said element terminating in an outer crop engaging edge leading upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on crop engaged by the rotor, said conditioning step comprising conditioning the crop by said outer edge of each said element, which is arranged to protrude outwardly from the rotor axis both at a lower part of said element close to the ground and at upper part of said element which is spaced from the ground, whereby said conditioning is effected by said outer edges of said elements of the rotor over a substantial proportion of the height of said rotor, and said conveying being effected by each said element which leads upwardly and rearwardly relative to the intended direction of rotation of said rotor so as to exert a lifting action on the crop, said outer edges being inclined upwardly and rearwardly over at least a major proportion of the height of the crop engaging region of the rotor.
 21. A method according to claim 20 including the steps of cutting crop by rotation of a rotary cutting means mounted coaxially with the crop engaging rotor, and conveying and conditioning the cut crop by the action of the crop engaging rotor.
 22. A method according to claim 21 including the step or rotating the rotary cutting means and the crop engaging rotor at different angular velocities.
 23. A method according to claim 20 including the steps of rotating two crop engaging rotors about respective vertical or near vertical axes which are spaced apart transversely relative to forward motion of the rotors, and rotating the two rotors in counter rotation in such a manner that crop is passed between the rotors upwardly and rearwardly from the front to the rear of the apparatus by a conveying action of both rotors. 